Covers for open-topped vehicular trailers, pickup truck beds, and the like are well known. Construction trucks often tow belly-dump and other open-topped trailers to transport granular material from a stockyard to a construction site. Such granular material typically comprises gravel or the like and is subject to being shaken or blown from the trailer during highway travel. Such debris may then strike following vehicles, potentially causing damage thereto. It is not uncommon for such debris to crack a windshield and/or chip the vehicle's paint, often resulting in the need for costly repair. In view of the high occurrence of damage caused by such debris, many states have enacted or are contemplating enacting legislation which will require all truck trailers to be covered during the transportation of such loads upon the highways.
It has been common practice to cover such loads with tarps to prevent debris from blowing or being shaken from the trailer. However, tarps are difficult and time consuming to install and are subject to being dislodged by impinging wind encountered during highway travel. Slidably or pivotally movable rigid covers have also been recently developed to cover the open tops of belly-dump and other such trailers.
One example of such a cover is provided in U.S. Pat. No. 4,585,267, issued to Friesen. The Friesen patent discloses a cover arrangement for a truck bed which is provided with a pair of rigid cover panels which extending along the length of the truck bed adapted to close at the longitudinal center line thereof. The cover panels are manually pivotable from the closed abutting position to an open position alongside the walls of the truck bed.
Another cover assembly is disclosed in U.S. Pat. No. 4,741,570, issued to Lovass. The Lovass cover assembly is intended for use upon a vehicle bed, such as that of a pickup truck, and includes a plurality of rigid, telescoping cover members longitudinally movable upon slide assemblies mounted along the side of the vehicle bed. Latching apparatus releasably secure the respective cover members over the front and rear end of the vehicle bed and permit opening of the cover to expose either the front portion or the rear portion of the bed. The Lovass device does not facilitate opening of the complete truck bed for maximum access thereto.
Although such trailer covers have proven generally suitable for their intended purposes, they possess inherent deficiencies which detract from their overall effectiveness in the marketplace. Pivoting covers, such as that of the Friesen patent, must be manually operated and therefore require time and effort to open and close. Sliding covers, such as that disclosed by Lovass, and also manually operated and additionally do not permit ready access to the entire trailer, but rather always cover a portion of the trailer's opening. As such, there exists a need in the art for a cover which may rapidly and automatically be articulated between open and closed positions, which will reliably remain in position during highway travel, and which provides full access to the interior of the trailer.